Authors:

Bennett N. Walker(George Washington University)

Guerman Pasmanik(Passat Inc., MD)

Akos Vertes(George Washington University)

Nanomaterials and mesostructures, such as laser induced silicon microcolumn
arrays (LISMA), offer new matrix-free platforms for laser desorption
ionization (LDI) of biomolecules. The morphology and surface chemistry of
LISMAs depend on the processing environment and the laser parameters. Column
diameters and lengths as well as periodicity, observed by AFM and SEM,
depend on processing conditions (processing medium, laser pulse energy,
pulse length and angle of incidence, etc.). Capillary waves at the molten
silicon--processing liquid interface seem to initiate the development of
LISMA structures. This is reflected by the correlation between the array
morphology and the processing liquid density and interfacial tension. Ion
yields from the various surfaces are dramatically affected by the pH of the
processing environment, indicating a strong influence of the OH-terminated
sites on the silicon surface. Ion generation from LISMAs also significantly
depends on the angle of the desorbing laser incidence, potentially
suggesting energy coupling through an antenna array mechanism.

To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2008.MAR.C1.167